This article explores identity and boundary issues in Native American works of fiction. It focusses on James Phillip Welch’s Winter in the Blood analyzing the central character’s shuffling between Native Americans’ and Whites’ cultures. By means of a postmodern analysis, this article highlights the notions of identity and boundary acquisition, showing on the one hand traditional or cultural identity, and on the other hand, the process of blurring lines between human beings. It comes to the conclusions that boundaries are blurred by means of physical and mental journeys, spirituality and humanism. It also concludes that identity is mutative.